System and method for tracking healing progress of tissue

ABSTRACT

A system and method for analyzing tissue healing may include an image capture device and a reference color marker of a predetermined color. A processing unit may be in communication with the image capture device, and be configured to receive image data from the image capture device. The image data may include image of a tissue site and the reference color marker. At least one image parameter may be adjusted based on at least a portion of the image of the reference color marker to normalize the image data. The normalized image data may be presented to a clinician.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to co-pending U.S. Provisional PatentApplication Ser. No. 60/845,993 filed on Sep. 19, 2006, the entirecontents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The principles of the present invention generally relate to a system andmethod for measuring a rate of biological tissue healing. Morespecifically, the principles of the present invention relate tomeasuring rate of biological tissue healing by normalizing color of animage of a tissue site and identifying colors of tissue site (e.g.,wound) areas that are associated with a phase of healing.

2. Description of the Related Art

The field of wound therapy has advanced in recent years. One of theadvancements of wound healing therapy has been the development of vacuumassisted wound healing. The application of reduced or negative pressureto a wound has been clinically shown to improve blood flow at the woundor tissue site, increase tissue growth, reduce infection, and improvehealing time. Caregivers and clinicians may use such vacuum assistedwound healing to treat a variety of chronic and acute wound types, suchas pressure ulcers, diabetic wounds, abdominal wounds, partial-thicknessburns, trauma wounds, flaps and grafts.

Background on Wounds and Wound Healing Processes

A wound is generally defined as a break in the epithelial integrity ofthe skin. Such an injury, however, may be much deeper, including thedermis, subcutaneous fat, fascia, muscle, and even bone. Proper woundhealing is a highly complex, dynamic, and coordinated series of stepsleading to tissue repair. Acute wound healing is a dynamic processinvolving both resident and migratory cell populations acting in acoordinated manner within the extra-cellular matrix environment torepair the injured tissues. Some wounds fail to heal in this manner (fora variety of reasons) and may be referred to as chronic wounds.

Following tissue injury, the coordinated healing of a wound willtypically involve four overlapping but well-defined phases: hemostasis,inflammation, proliferation, and remodeling. Hemostasis involves thefirst steps in wound response and repair that are bleeding, coagulation,and platelet and complement activation. Inflammation peaks near the endof the first day. Cell proliferation occurs over the next 7-30 days andinvolves the time period over which wound area measurements may be ofmost benefit. During this time fibroplasia, angiogenesis,re-epithelialization, and extra-cellular matrix synthesis occur. Theinitial collagen formation in a wound typically peaks in approximately 7days. The wound re-epithelialization occurs in about 48 hours underoptimal conditions, at which time the wound may be completely sealed. Ahealing wound may have 15% to 20% of full tensile strength at 3 weeksand 60% of full strength at 4 months. After the first month, adegradation and remodeling stage begins, wherein cellularity andvascularity decrease and tensile strength increases. Formation of amature scar often requires 6 to 12 months.

Efforts in the Related Art to Measure Wound Healing Processes

Because wound treatment can be costly in both materials and professionalcare time, a treatment that is based on an accurate assessment of thewound and the wound healing process can be essential. There are a fewwound parameters that may assist a clinician in determining healingprogress of a wound. For example, wound area and volume measurements mayprovide a clinician with knowledge as to whether or not a wound ishealing and, if the wound is healing, how rapidly the wound is healing.Wound assessment is an important process to properly treating a wound asimproper or incomplete assessment may result in a wide variety ofcomplications. Infections at a tissue site that go untreated may resultin permanent damage or even death to a patient.

While wound measurement is a parameter that is beneficial to a clinicianto determine wound healing progress, the size of the wound may notprovide a clinician with enough information to fully assess whether orhow a wound is healing. For example, while a wound may reduce in size,certain parts of a wound may become infected. A clinician often examineswound tissue for its color and texture to determine how a wound ishealing. Wound tissue includes a wound bed and periwound areas or woundedges. Health of a wound may be determined by color of tissue.Conversely, certain problems may be detected from the color of woundtissue. For example, normal granulation tissue has a beefy, red, shinytextured appearance and bleeds readily, whereas necrotic tissue (i.e.,dead tissue) may either be yellow-gray and soft, generally known as“slough” tissue, or hard and black/brown in color, generally known as“eschar” tissue. A clinician may observe and monitor these and otherwound tissues to determine wound healing progress of the overall woundand specific wound regions.

While consistent wound measurement is a factor for accuratelydetermining changes in wound size, so too is measurement of differentwound tissue. Although texture of wound tissue is indicative of woundhealing, color can also be used. One problem with color of wound tissueis that colors can often be altered depending on lighting. For example,a wound under incandescent lighting may have a different colorappearance from a wound under fluorescent lighting. Also, differentclinicians may have different color perception. For example, oneclinician may have strong color perception while another may be colorblind in one or more colors, thereby providing both with differentinterpretation of color of wound tissue.

While a number of techniques have been developed to estimate the size ofa wound, there are but a few techniques for measuring different types ofwound tissue. One technique includes placing a clear film over a woundand using a soft-tipped pen to color different wound tissues on thefilm, thereby making a record of the wound tissues. This process may berepeated to record wound healing over time. This process also suffersdue to lighting conditions, color sensitivity of clinicians, capabilityof a clinician to accurately draw on the clear film, and inherentproblems from contacting the film onto the wound tissue. Anothertechnique includes making an outline of the wound on the film, scanningthe image into a computer, and then drawing an estimation of thedifferent wound tissue on the computer. This technique also suffers frominaccuracy.

SUMMARY OF THE INVENTION

To enable a clinician to monitor wound healing by monitoring woundtissue in an accurate manner, the principles of the present inventionprovide a wound healing assessment system and process to enable aclinician to accurately assess wound healing. One embodiment providesfor a reference color marker to be placed at a tissue site whencapturing an image of the tissue site so that the reference color markermay be used by an image processing system to alter at least one imageparameter, such as brightness, to normalize the color of the tissue siteto be accurate with respect to images the same or different tissuesites. In one embodiment, once the tissue site is normalized, aclinician may select wound regions that have certain colors or textureassociated with a stage of wound healing using a touch-sensitiveelectronic display or pointing device, such as a computer mouse. Inaddition or alternatively, the image processing system may identify oneor more wound tissue regions that have a color within a range of colorsor wavelengths. The identified wound tissue may thereafter be used todetermine area of the wound tissue region(s), thereby providing aclinician with an accurate assessment of wound tissue that is associatedwith a healing stage. Multiple ranges of colors may be used to identifydifferent wound tissue regions that are associated with different woundhealing stages. The wound assessment process may be repeated to monitorthe wound healing process over time.

One embodiment of a system for analyzing tissue healing may include animage capture device and a reference color marker of a predeterminedcolor. A processing unit may be in communication with the image capturedevice, and be configured to receive image data from the image capturedevice. The image data may include image of a tissue site and thereference color marker. At least one image parameter may be adjustedbased on at least a portion of the image of the reference color markerto normalize the image data. The normalized image data may be presentedto a clinician.

One embodiment for analyzing tissue healing may include capturing animage including a tissue site and a reference color marker. At least oneimage parameter may be adjusted based on at least a portion of the imageof the reference color marker to normalize color of the image. The colornormalized image may be presented to a clinician.

Another embodiment for analyzing tissue healing may include capturing animage including a tissue site. A clinician may be enabled to definemultiple regions of the image of the tissue site, where at least two ofthe regions of the image defining tissue type are at different stages oftissue healing. An area of each of the at least two regions of the imagedefining tissue type at different stages of tissue healing may becalculated and displayed for the clinician. A reference color marker maybe utilized to provide for color normalization of the image of thetissue site.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an illustration of an exemplary patient environment using atissue treatment system in accordance with the principles of the presentinvention;

FIG. 1B is an illustration of an exemplary tissue site of a patient andcolor reference marker for use in normalizing an image of the tissuesite;

FIG. 2 is a block diagram of an exemplary processing system for use ingenerating images and defining and normalizing tissue color;

FIG. 3 is a block diagram of exemplary software modules executable bythe processing system of FIG. 2 to perform tissue defining and coloradjustment functions in accordance with the principles of the presentinvention; and

FIG. 4 is a flow diagram of an exemplary process for performing a coloradjustment function to normalize color of a tissue site; and

FIG. 5 is a flow diagram of an exemplary process for analyzing a tissuesite.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1A, an exemplary patient environment showing a patient102 having a tissue site 104 using a tissue treatment system 106 inaccordance with the principles of the present invention. In oneembodiment, the tissue treatment system 106 may be a vacuum assistedtherapy device. Alternatively, the tissue treatment system 106 may beany system that is generally utilized to assist a patient in the processof tissue treatment, such as wound healing. Still yet, the tissuetreatment system 106 may be any computing system that is configured toutilize software as described further herein to assist a caregiver orclinician with monitoring healing of the tissue site 104.

A color reference marker 108 is shown to be placed in association withthe tissue site 104 so that an image capture device 110 may capture animage of both the tissue site 104 and color reference marker 108 in aphotograph. The image capture device 110 may be a digital camera, mobiletelephone, or any other electronic device configured to capture an imagein a digital or analog format. In general, to expedite capturing andworking with an image of the tissue site 104, a digital camera that isconfigured with a wireless communications link 112 with the tissuetreatment system 106 may be used. The wireless communications link 112may be an 802.11 wireless communications link or WiFi communicationslink. Any other wireless communications link protocol may be utilized.Alternatively or additionally, a wired connection may be made betweenthe tissue treatment system 106 and the image capture device 110. Stillyet, the image capture device 110 may utilize a memory device (notshown) that may be transferred between electronic devices. The memorydevice may include flash memory, mini-DVD, or any other memory devicewith which the tissue treatment system 106 may be compatible.

The term “tissue site” as used herein refers to a wound or defectlocated on or within any tissue, including but not limited to, bonetissue, adipose tissue, muscle tissue, neuro tissue, dermal tissue,vascular tissue, connective tissue, cartilage, tendons, or ligaments.The term “tissue site” may further refer to areas of any tissue that arenot necessarily wounded or defective, but are instead areas in which itis desired to add or promote the growth of additional tissue. Forexample, reduced pressure tissue treatment may be used in certain tissueareas to grow additional tissue that may be harvested and transplantedto another tissue location.

The term “clinician” is used herein as meaning any medical professional,user, family member of a patient, or patient who interacts or interfaceswith a reduced pressure delivery system.

The color reference marker 108 is a device that is used by the tissuetherapy system 106 for normalizing color of an image of the tissue site104. The color reference marker 108 may be virtually any color, but onethat the tissue treatment system 106 has been configured to use tonormalize color of a tissue site. For example, the color referencemarker 108 may be white, black, grayscale, Pantone matching system (PMS)spot color, two color, four color, or any other color combination. Theterm “color” is used herein to mean any color or any shade in any scale(e.g., grayscale). In addition, the color reference marker 108 may bepaper, plastic, or any other material. In one embodiment, the colorreference marker 108 is a sterilized material to avoid infecting thetissue site 104. The color reference marker 108 may further include anadhesive on one side to enable a clinician to adhere the color referencemarker 108 to the patient 102 or an object within view of the tissuesite 104 by the image capture device 110. Alternatively, the clinicianmay use a tape or other temporary fastener to locate the color referencemarker 108 at or near the tissue site 104.

In terms of normalizing color of an image of the tissue site 104, thetissue treatment system 106 may import or otherwise receive an image ofthe tissue site 104 and color reference marker 108 captured by the imagecapture device 110. An electronic display 114 may be utilized to displayan image 116 of the tissue site 104′ and color reference marker 108′. Inone embodiment, the electronic display 114 is a touch-sensitiveelectronic display that responds to a stylus (not shown) or finger toenable a clinician to interact with images and controls displayed on theelectronic display 114.

Soft-buttons 118 a-118 n or other graphical control elements may bedisposed on the electronic display 114 to enable the clinician to entera mode, edit an image, or perform any other control as definable by adeveloper and executed by the tissue treatment system 106. For example,a soft-button 118 a may enable a user to normalize the image 116 bycorrecting the color reference marker 108′ to a predetermined color.Another soft-button 118 b may cause the tissue treatment system 106 toenter a tissue trace mode to enable a clinician to trace a perimeter ofa wound or other tissue site, thereby defining the tissue site. Anothersoft-button 118 c may cause the tissue treatment system 106 to enter atissue type trace mode, where a clinician may be able to define orotherwise identify various tissue types (e.g., eschar tissue) of thetissue site 104 by tracing or applying indicia at the perimeter of thedifferent tissue types. Another soft-button 118 n may provide forzooming in and out of the image. Another soft-button may enable savingthe image to an image database on the tissue treatment system 106. Itshould be understood that any function to enable the clinician tocollect, manipulate, edit, define tissue types, etc., may be provided onthe tissue treatment system 106.

Referring to FIG. 1B, the tissue site 104 of patient 102 and colorreference marker 108 for use in normalizing an image of the tissue siteare shown. The color reference marker 108 is shown to be white. However,the color reference marker 108 may be any color, as previouslydescribed. The tissue site 104 is shown to have a variety of tissuetypes. For example, wound edges or periwound skin 120 may be pink/whiteand define tissue site 104, granulation tissue 122 may be red/deep pinkthat is moist with a bumpy appearance, necrotic tissue 124 may beblack/brown in color and be hard, and slough tissue 126 may beyellow/white in color and be loose. It should be understood that othertissue types that occur during wound or tissue healing may be identifiedby color or texture. By including the color reference marker 108 in animage of the tissue site 104, adjustment to image of the color referencemarker 108 may adjust color of the image of the tissue site to benormalized.

The tissue treatment system 106 may be configured to perform coloradjustment on an entire image based on at least a portion of a collectedimage of the reference color marker 108. The reference color marker 108may be a predefined or predetermined color and adjustment of the imagemay include changing the image of reference color marker 108 until theimage substantially matches the predetermined color. Being substantiallymatched to a predetermined color may be that each color component iswithin 1% of a predetermined color percentage value for respective colorcomponents, such as red 18%±1%, green 27%±1%, and blue 40%±1%, if an RGBcolor scheme is used. Alternatively, being substantially matched to apredetermined color may be that the aggregate color formed by colorcomponents is within 3% of a predetermined color (e.g., a PMS spotcolor, such as Blue PMS-300, if a four color PMS color scheme is used).The tissue treatment system 106 may be calibrated such that when animage of the reference color marker 108 is color adjusted tosubstantially match a predefined color (e.g., pure white), the image ofthe tissue site 104 is normalized. Adjustment of color may be performedin a variety of manners, as understood in the art. In accordance withthe principles of the present invention, adjustment of color may includechanging brightness, contrast, hue, saturation, color balance, colorlevel, or any other adjustment that alters the image of the referencecolor marker 108. For example, if the reference color marker 108 iswhite, a white balance, which is a process of removing colors so that anobject, such as the reference color marker 108, that is true whiteappears true white in an image. If, for example, incandescent light isused to light a wound, the reference color marker 108, which may bewhite, captures the incandescent light and the color caused by theincandescent light is removed from the image of the reference colormarker 108 until the image of the reference color marker 108 is whitewithin a predetermined tolerance. The color adjustment of the referencecolor marker 108 may be applied to the image of the tissue site, therebynormalizing the color of the tissue site. By normalizing the color ofthe tissue site, lighting conditions that may vary over time, betweenrooms, between facilities, etc., are factored out.

Referring to FIG. 2, an exemplary processing system 200 for use ingenerating images and defining and normalizing tissue site color isshown. The processing system 200 may include a processing unit 202 thatexecutes software 204. The processing unit 202 may be configured withone or more processors that are the same or different types. Forexample, the processing unit 202 may include a general processing unitand a digital signal processing unit configured to perform imageprocessing to perform color adjustments in accordance with theprinciples of the present invention.

The processing unit 202 may further be in communication with (i) amemory 206 for storing data and software code, (ii) input/output (I/O)unit 208 for communicating with other devices and systems, such as adigital camera, wirelessly, via a wire, or via a memory input device(not shown), (iii) storage unit 210 that may store one or more datarepositories 212 a-212 n (collectively 212), such as a database havingone or more files, and (iv) electronic display 214 that may or many notbe touch-sensitive. The software 204 may be configured to interface witheach of the other devices (e.g., electronic display 214) to performtissue site image collection, for example, and color adjust the image ofthe tissue site by adjusting color for an image of a reference colormarker.

Referring now to FIG. 3, software modules 300 of software 204 (FIG. 2)executable by processing unit 202 (FIG. 2) may be utilized to performwound defining and color adjustment functions in accordance with theprinciples of the present invention. The software modules 300 shown areexemplary and may include additional and/or other software modules toprovide the same or similar functionality.

Define tissue site module 302 is a software module that may beconfigured to enable a clinician to display an image of a tissue siteand either trace or identify consecutive locations on a perimeter of atissue site using a touch-sensitive electronic display or pointingdevice (e.g., computer mouse) and estimate a trace of the perimeterbetween each of the consecutive locations on the perimeter. The areawithin the trace or estimated trace defines the tissue site, which, inone embodiment, may be a wound.

Define tissue site regions module 304 is a software module that may beconfigured to enable a clinician to define one or more sub-regionswithin the tissue site defined by the define tissue site module. Indefining the sub-region(s), the clinician may trace perimeter(s) of thesub-region(s) being displayed on an electronic display or otherwisecause the perimeter(s) to be defined. The tissue site regions, orsub-regions of the tissue site, may be the same or different tissuetypes that have developed as different stages of tissue healing. Forexample, the tissue site regions may include necrotic or slough tissue.In another embodiment, the define tissue site regions module 304 may beconfigured to automatically or semi-automatically locate tissue type inthe same or similar tissue healing stage by searching for any tissuewithin a color or wavelength range that defines the tissue healingstage. For example, the clinician may identify a color of tissue in theimage of the tissue site and the module 304 may locate all of the tissuewithin the tissue site that is within a percentage color range usingindividual colors (e.g., red, green, blue parameters having a totalpercentage value within a predetermined range, such as 2 percent),brightness, or other image parameter that identifies the tissue to bewithin the same tissue healing stage. A trace may be created around thetissue regions located by the module 304 estimated to be within the sametissue healing stage.

Normalize tissue site color module 306 is a software module that may beconfigured to normalize color of an image of a tissue site based oncolor adjustment to at least a portion of an image of a reference colormarker to substantially match a predetermined color, as previouslydescribed herein.

Generate outline module 308 is a software module that may be configuredto generate an outline of a tissue site or tissue region within a tissuesite based on selected locations by a clinician to define the tissuesite or tissue region. The generate outline module 308 may also be usedif the clinician performs a trace, but to a lesser extent and,optionally, to determine points or smoothen the trace.

Identify tissue site regions module 310 is a software module that may beconfigured to generate curvilinear lines (i.e., lines that may havestraight and curved portions) to highlight or otherwise define tissuesite regions. In addition, the identify tissue site regions module 310may be utilized to generate a graphical image, such as a solid color,that is opaque or translucent to show a clinician the area(s) of atissue site region. In one embodiment, different colors, patterns, orother graphical image may be utilized to identify different tissue types(e.g., necrotic tissue with brown or black graphical image versusgranulation tissue with red graphical image).

Compute tissue site regions area module 312 is a software module thatmay be configured to compute area of one or more tissue site regions ofthe same or different tissue types. By determining area of tissue siteregions, a clinician can monitor healing or treatment progress of atissue site over time. In one embodiment, the software may enable for atissue site depth to be entered and the module 312 may generate a tissuesite volume value. The tissue site area and/or volume may be displayedon the electronic display, optionally within a tissue site region, alongwith the image of the tissue site and tissue site regions.

Manage tissue site image database module 314 is a software moduleconfigured to store tissue site images in one or more databases. Themodule 314 may be configured to store images associated with patients,by date, by tissue site type (e.g., wound), by treatment identifier, byclinician, or by any other identifier. The module 314 may store eachcaptured image separately from traces, graphical images that over orunderlay the image of the tissue site, calculated tissue site area andvolume, date and time information, or any other information other thanthe image so that a clinician may retrieve the raw tissue site imageswithout any other information, and the other information may be storedin association with the tissue site images so that the information canbe retrieved simultaneously or separately. In one embodiment, theinformation associated with the tissue site images may be stored in atable or other format to enable a clinician to perform searches, sorts,tabulations, or any other database function. Still yet, the module 314may store raw and color normalized tissue site images.

Referring to FIG. 4, a process 400 for performing a color adjustmentfunction to normalize color of a tissue site is presented. The process400 starts at step 402 and at step 404, an image including a tissue siteand reference color marker may be captured. The reference color markermay be any color, such as white, and be used to normalize color of thetissue site to offset lighting when the image of the tissue site iscaptured. At step 406, one or more image parameters may be adjustedbased on at least a portion of the image of the reference color markerto normalize color of the image. The adjustment may be any coloradjustment to cause the image of the reference color marker to be withina range or tolerance of or substantially match a predefined colortolerance (e.g., pure white (i.e., yellow, cyan, magenta, and blackvalues at 0%) ±1% of any color component). Other range percentages maybe utilized in accordance with the principles of the present invention.By adjusting the image (or portion of the image) of the tissue site, thetissue site may be color normalized to remove lighting conditions in theroom that the image of the tissue site is captured. At step 408, thecolor normalized tissue site image is presented to the clinician. Theprocess ends at step 410. In one embodiment, the clinician may use thecolor normalized tissue site image to define the tissue site by tracingaround the perimeter of the tissue site. Alternatively, a softwaremodule that locates an edge between different colors or textures of thetissue site may estimate the perimeter of the tissue site. In adjustingthe color, the color may be adjusted using one or more different imagecorrection techniques, including white balancing, adjustment to hue,brightness, or other color adjustment function as understood in the art.

Referring to FIG. 5, a process 500 for analyzing tissue healing isshown. The process 500 starts at step 502. At step 504, an imageincluding a tissue site may be captured. At step 506, a clinician may beenabled to define multiple regions of the image of the tissue site,where at least two of the regions of the image defining tissue type areat different stages of tissue healing. An area of each of the regions ofthe image defining tissue type at different stages of tissue healing maybe calculated at step 508. The calculated areas may be displayed at step510. The process ends at step 512. A reference color marker may beutilized to provide for color normalization of the image of the tissuesite.

Although the principles of the present invention have been described interms of the foregoing embodiments, this description has been providedby way of explanation only, and is not intended to be construed as alimitation of the invention. Those skilled in the art will recognizemodifications of the present invention that might accommodate specificpatient and tissue treatment environments.

1. A system for analyzing tissue healing, said system comprising: animage capture device; a reference color marker of a predetermined color;a processing unit in communication with said image capture device, andconfigured to: receive image data from said image capture device, theimage data including image of a tissue site and said reference colormarker; adjust at least one image parameter based on at least a portionof the image of said reference color marker to normalize the image data;and present the normalized image data to a clinician.
 2. The systemaccording to claim 1, wherein said processing unit, in adjusting the atleast one image parameter, changes color of the at least a portion ofthe image of said reference color element to substantially match apredetermined color, wherein said processing unit is further configuredto change color of the image of the tissue site in the same manner asthe color of the image of the reference color element is changed.
 3. Thesystem according to claim 2, wherein said processing system is furtherconfigured to: enable the clinician to identify at least one region ofthe tissue site that is within a particular stage of tissue healing. 4.The system according to claim 3, wherein the region of the tissue sitedefines necrotic tissue, granulation tissue, or slough tissue.
 5. Thesystem according to claim 3, wherein said processing unit is furtherconfigured to calculate area of the at least one region of the tissuesite.
 6. The system according to claim 5, further comprising anelectronic display, wherein said processing unit is further configuredto display the tissue site and identify the region of the tissue sitewithin the tissue healing stage on said electronic display.
 7. Thesystem according to claim 2, wherein said processing unit is furtherconfigured to: compare colors in the adjusted color image of the tissuesite to a range of colors defining a tissue type within a tissue healingstage; and determine area of the tissue type within the tissue healingstage.
 8. The system according to claim 7, wherein said processing unitis further configured to repeat comparing and determining for multipletissue healing stages.
 9. The system according to claim 1, wherein saidreference color marker is a card.
 10. The system according to claim 1,wherein said reference color element is white.
 11. The system accordingto claim 10, wherein the at least one image parameter includes a whitebalance image parameter.
 12. A method for analyzing tissue healing, saidmethod comprising: capturing an image including a tissue site and areference color marker; adjusting at least one image parameter based onat least a portion of the image of the reference color marker tonormalize color of the image; and presenting the color normalized imageto a clinician.
 13. The method according to claim 12, wherein adjustingincludes changing color of the at least a portion of the image of thereference color marker to substantially match a predetermined color,thereby changing color of the image of the tissue site in the samemanner as the color of the image of the reference color marker ischanged.
 14. The method according to claim 13, further comprisingenabling the clinician to identify at least one region of the tissuesite that is within a particular stage of tissue healing.
 15. The methodaccording to claim 14, wherein enabling the clinician to identify atleast one region of the tissue site includes enabling the clinician toidentify that the at least one region of the tissue site is necrotictissue, granulation tissue, or slough tissue.
 16. The method accordingto claim 14, further comprising calculating area of the at least oneregion of the tissue site.
 17. The method according to claim 16, furthercomprising displaying the tissue site and identify the at least oneregion of the tissue site within the tissue healing stage on thedisplayed tissue site.
 18. The method according to claim 13, furthercomprising: comparing colors in the adjusted color image of the tissuesite to a range of colors defining tissue type within a tissue healingstage; and determine area of the tissue type within the tissue healingstage.
 19. The method according to claim 18, further comprisingrepeating comparing and determining for multiple tissue healing stages.20. The method according to claim 11, wherein capturing an imageincluding a reference color marker includes capturing an image of awhite reference color marker.
 21. A method for analyzing tissue healing,said method comprising: capturing an image including a tissue site;enabling a clinician to define multiple regions of the image of thetissue site, at least two of the regions of the image defining tissuetype at different stages of tissue healing; calculating an area of eachof the at least two regions of the image defining tissue type atdifferent stages of tissue healing; and displaying the calculated areas.22. The method according to claim 21, wherein capturing further includescapturing a reference color marker, and further comprising: adjustingthe image of the reference color marker to a predetermined color; andadjusting the image of the tissue site the same as the adjustment to theimage of the reference color marker to color normalize the image of thetissue site.
 23. The method according to claim 22, wherein adjusting theimage of the tissue site includes color normalizing the image of thetissue site.
 24. The method according to claim 21, further comprisingdisplaying indicia on the image of the tissue site to indicate the atleast two regions of the image defining tissue type at different stagesof tissue healing.
 25. The method according to claim 21, furthercomprising: automatically identifying other regions of the image of thetissue site that have color substantially the same as color within aregion defining tissue type at a stage of tissue healing; andcalculating area for each of the regions defining tissue type at thesame stage of tissue healing.